Which pinion for my buggy? (conversion)

[simplechamp]

What kind of buggy do you have? I'm sure someone around here knows the diff ratio.

It's generally accepted to gear between 30-40mph when testing a new setup. Always better to start conservatively, and speed up from there if your temps are staying within safe ranges. Having to spend another $10 on the next larger larger pinion is much less of a headache than sending in a fried ESC for warranty or having to buy a new one!